As home inspectors, we see mold growing in all sorts of places. A few years ago our clients started asking if we would collect samples for laboratory analysis to determine if the molds were "toxic." After extensive research into mold-related problems, we decided to help our clients by collecting samples when they want them, but also to help determine the causes of the mold, and to develop effective solutions.

The purpose of this article is to provide a background to potential problems relating to molds and excessive moisture, and to offer a few solutions.
Historically, mold issues have been addressed primarily in the commercial sector by specially trained industrial hygienists, who use a wide range of skills and techniques to solve indoor air quality (IAQ) problems found in office buildings and other large structures. Molds and problem air quality issues have recently become much more apparent in homes, creating the need for a new approach.

First, the Basics
A mold is a type of fungus. Molds grow everywhere and can be found in some amount in every room or space. If you can see mold or if you notice an earthy or musty odor, you can assume there is a potential mold problem. Molds need a food source to live and tend to grow on porous cellulose materials such as wood, ceiling tiles, and sheet rock or gypsum board. Molds especially like dry wall or sheet rock because it is porous and contains nutrients the molds can feed on.

Molds can also grow on hard surfaces, such as tile or metal window frames-or even glass-by living on the dust that sticks to cool, damp surfaces. These areas are easy to clean with household detergent.

There are three primary ways molds can cause harm.
Molds can be toxic, infectious, or allergenic. Molds that produce mycotoxins such as Stachybotrys and Trichoderma are considered "toxic molds," and are thought by some to present a greater hazard than common molds such as Cladosporium and Alternaria. Our research shows that Penicillium-Aspergillus molds are most likely to cause allergy or asthma-related problems in homes.

The popular term "toxic mold" is considered by many experts to be incorrect or even misleading.

Toxicity is based on dosage.
Any substance is toxic if ingested in sufficiently large quantities (including coffee, tea, or even pure water). While a specific mold would be toxic if ingested or inhaled in large quantities, such exposures appear to be rare. Mycotoxins are toxic substances produced by molds. Mycotoxins often adhere to surfaces and do not easily become airborne where they can be inhaled in quantities sufficient to create a toxic effect.

Some fungi, such as Aspergillus and Fusarium, can cause infectious diseases. Most infectious diseases caused by fungi occur in individuals who are immune-compromised, such as those with severe burns or HIV; those hospitalized for cancer treatment; and individuals who have lung diseases. People with other respiratory illnesses, the elderly, and infants are also vulnerable to infectious molds. The immune system of a healthy person can easily ward off many infectious attacks, although fungi from bird or bat droppings can cause a flu-like illness even in healthy individuals.

Allergenic molds are much more likely to cause problems for humans. Mold allergies are not uncommon and are routinely diagnosed by allergy specialists. Mold spores are inhaled into the lungs with almost every breath we take and those of us who are highly sensitive to molds, dust, dust mites, and other minute particles need to take special care to maintain a healthy indoor environment.

Mold Sources
Significant mold growth does not occur unless there is sufficient moisture, typically caused by excessive air humidity, water entry, or plumbing leaks. Excessive humidity caused by poor ventilation after bathing, showering, boiling water, cooking, and other moisture-producing activities are the primary sources of mold growth in the home. Improperly installed windows, leaky roofs, moist or damp basements, and excessively damp subfloor areas can contribute to high moisture and interior mold growth.

There are numerous ways to test for mold, and no single method is effective for each situation. Mold can grow inside walls, in building materials, and in those areas that are not routinely occupied. Mold spores may not show up in air sampling tests if they are not airborne at the time of sampling.

Primary Sampling Techniques
	Outdoor Air Samples establish a base reading.
	Indoor Air Samples determine relative mold spore concentration in the air.
	Swab Sample: A swab is wiped on a surface to collect mold samples.
	Tape Lift:A strip of tape is used to collect the sample. The tape is placed on a glass slide for microscopic examination.
	Carpet Sample: Tape is used to collect a sample from the carpet surface, or a sample is vacuumed from an area of carpet.
	Wall Cavity Sample: Air is drawn through small holes drilled in the wall and sampled for spore activity.
	Duct Test: Dust from furnace ducting or filters is sampled and tested.

How many samples should be taken?
A minimum of six to eight samples is usually necessary to determine if the number of mold spores inside a home is significantly elevated at the time of our review. Conditions that produce high spore counts in the air will change throughout the day depending on occupants' activities.

How soon will we get results?
Most labs provide a three to five day turn-around. Results can be obtained within 48 hours for an extra fee.

How much will this cost?
Our minimum fee for a Preliminary Indoor Air Quality Review is $850 and includes six samples, a report on possible causes for excessive moisture, and recommendations to eliminate and prevent future mold activity. Additional samples are $75 each.

We discount this fee by $200 if the inspector is already on-site to provide other services, such as a home inspection.

While we believe the only way to know if potentially problematic spores are present is to have samples analyzed by an approved scientific laboratory, some clients prefer a non-sample consultation. We provide consultation-only reviews for $400 minimum, depending on the size and complexity of the areas to be reviewed. The purpose of a consultation may be to assess the cause of mold growth and provide recommendations for remediation.

The Bottom Line
It is important to keep indoor spaces well ventilated and relatively dry. If you have reason to believe that you or others in your family are especially sensitive to molds, and if you see mold or smell musty odors, you should consider having samples collected and sent to an approved laboratory for analysis.
Our inspectors have extensive experience locating and solving problems related to excessive moisture in homes and commercial properties.

At Star Inspection Group, it is our goal not only to provide the best sampling available, but also to assist our clients in finding practical solutions to potential mold and other indoor air quality problems.